Study: Topical med residues impact environment

June 1, 2010

A new study on pollution from active pharmaceutical ingredients (APIs) has uncovered a previously unrecognized means by which drug residues are released into the environment. The study's authors say the findings could lead to new ways to control environmental pollution from APIs.

Key Points

Henderson, Nev. - A new study on pollution from active pharmaceutical ingredients (APIs) has uncovered a previously unrecognized means by which drug residues are released into the environment.

The study's authors say the findings could lead to new ways to control environmental pollution from APIs.

Dr. Ruhoy and her colleague identified the potential new source of APIs by reviewing hundreds of studies on the metabolism and use of medications.

Researchers focused on APIs in medications that are applied to the skin, and then are washed off the body or clothes and down drains, or are excreted through sweat glands onto clothes that are then washed.

Thus, steroids (such as cortisone and testosterone), acne medicine, antimicrobials, narcotics and other substances can enter the environment.

"I was motivated to do this study because my previous research and focus had been on pharmaceutical residues in the environment - the sources, the significance and what approaches should be taken to not only further assess the issue, but to minimize the extent of it," Dr. Ruhoy says.

"One such source that had not been previously discussed was the removal of medications from our skin into our environment by way of bathing."

Greater impact

Dr. Ruhoy notes that some APIs in topical medications could have potentially greater impact on the environment than APIs released in bodily wastes, because topical APIs released through bathing and showering are unmetabolized and at full strength.

Those released into the environment in feces and urine are at lesser strength because they have been metabolized in the liver and kidneys before being excreted, she says.

"Pharmaceutical compounds are considered an 'emerging contaminant,' and as such the federal government has certainly directed more recent interest to further research on the topic," Dr. Ruhoy says.

"There is no question we live in a chemical sea, and pharmaceutical compounds are but just one type of chemical. There is also no question that pharmaceuticals play an important and sometimes vital role in the treatment and management of patients.

"But we must recognize that pharmaceuticals have afterlives and an environmental footprint," she adds. "Some research has demonstrated an ecological impact in species living in or off of contaminated waters. The effects on humans of exposure to pharmaceutical residues in the environment is largely unknown."

Until further research makes clearer the effects of these residues on humans, Dr. Ruhoy suggests prudent dose prescription as one of several steps toward mitigating the problem.

"There are collateral benefits to these practices, as not only do we improve healthcare and reduce healthcare costs, but also reduce the likelihood of drug compounds in the ecosystem," Dr. Ruhoy says.

"There are some dispensing technologies currently in development to assist patients in retrieval of minimal dose, and prebathing rituals to remove remaining medication from the skin can help."

She adds that dermatologists are in a prime position to educate patients and raise awareness.

"This would include instruction on how best to apply lotions, gels and creams without exceeding the minimal dose," Dr. Ruhoy says. "An awareness of the issue will also help motivate patients to heed advice and guidance from their physician."